Segment Information (Costs Incurred on Long-lived Assets) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Segment Reporting Information [Line Items]
Cost incurred on long-lived assets	$ 511,093	$ 573,052	$ 615,487
Operating Segments [Member] | North America [Member] | Carolinas Richmond [Member]
Segment Reporting Information [Line Items]
Cost incurred on long-lived assets	51,647	31,175	82,600
Operating Segments [Member] | North America [Member] | Chicago Milwaukee [Member]
Segment Reporting Information [Line Items]
Cost incurred on long-lived assets	18,294	13,483	21,698
Operating Segments [Member] | North America [Member] | Florida [Member]
Segment Reporting Information [Line Items]
Cost incurred on long-lived assets	38,312	43,594	45,152
Operating Segments [Member] | North America [Member] | Houston [Member]
Segment Reporting Information [Line Items]
Cost incurred on long-lived assets	25,638	96,681	70,903
Operating Segments [Member] | North America [Member] | Lehigh Central PA [Member]
Segment Reporting Information [Line Items]
Cost incurred on long-lived assets	176,386	165,319	105,725
Operating Segments [Member] | North America [Member] | Minnesota [Member]
Segment Reporting Information [Line Items]
Cost incurred on long-lived assets	11,023	41,259	28,966
Operating Segments [Member] | North America [Member] | Philadelphia [Member]
Segment Reporting Information [Line Items]
Cost incurred on long-lived assets	57,691	34,122	32,012
Operating Segments [Member] | North America [Member] | Southeastern PA [Member]
Segment Reporting Information [Line Items]
Cost incurred on long-lived assets	13,110	9,047	39,638
Operating Segments [Member] | North America [Member] | Other Segments [Member]
Segment Reporting Information [Line Items]
Cost incurred on long-lived assets	107,500	125,412	172,495
Operating Segments [Member] | United Kingdom [Member] | United Kingdom [Member]
Segment Reporting Information [Line Items]
Cost incurred on long-lived assets	$ 11,492	$ 12,960	$ 16,298